Reaktion #1833225

Reaktionsgleichung

n-BuLi

iodine

2,2,3,3,7-Pentafluoro-2,3-dihydrobenzofuran

lithium diisopropylamide

→

title compound

Ausbeute 25.0%

2,2,3,3,7-Pentafluoro-6-iodo-2,3-dihydrobenzofuran

Ausbeute 25.0%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigequenched by addition of saturated NH4Cl
2. 2
   workup.ADDITIONThe mixture was treated with 10% NaHSO3 (15 mL)
3. 3
   Extraktionextracted twice with diethyl ether (15 mL portions)
4. 4
   TrocknenThe combined extracts were dried (Na2SO4)
5. 5
   Sonstigeevaporated
6. 6
   SonstigeThe residue was purified by reverse-phase
7. 7
   WaschenHPLC eluting with 85% acetonitrile-water

Vorschrift

2,2,3,3,7-Pentafluoro-2,3-dihydrobenzofuran (500 mg, 2.4 mmol) was added in portions to a −70° C. solution of lithium diisopropylamide (LDA) prepared in dry tetrahydrofuran (7 mL) from disopropylamine (380 mg, 3.8 mmol) and 2.5 M n-BuLi (1.4 mL, 3.6 mmol). After 40 min at −70° C. a solution of iodine (1.0 g, 4.0 mmol) in tetrahydrofuran (5 mL) was added over 15 min. After 20 min at −70° C., the mixture was warmed to −20° C. and quenched by addition of saturated NH4Cl. The mixture was treated with 10% NaHSO3 (15 mL), stirred for 10 min and extracted twice with diethyl ether (15 mL portions). The combined extracts were dried (Na2SO4) and evaporated. The residue was purified by reverse-phase HPLC eluting with 85% acetonitrile-water to afford the title compound (200 mg, 25%): 1H NMR (400 MHz, CDCl3) δ 7.25 (dd, J=8.1, 4.8 Hz, 1H), 6.63 (dd, J=8.0, 1.1 Hz, 1H), 4.13 (s, 3H); EIMS m/z 336.

Quelle